1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 // 28 // Tests of profiler-related functions from log.h 29 30 #include <stdlib.h> 31 32 #include "v8.h" 33 34 #include "api.h" 35 #include "codegen.h" 36 #include "log.h" 37 #include "isolate.h" 38 #include "cctest.h" 39 #include "disassembler.h" 40 #include "vm-state-inl.h" 41 42 using v8::Function; 43 using v8::Local; 44 using v8::Object; 45 using v8::Script; 46 using v8::String; 47 using v8::Value; 48 49 using v8::internal::byte; 50 using v8::internal::Address; 51 using v8::internal::Handle; 52 using v8::internal::Isolate; 53 using v8::internal::JSFunction; 54 using v8::internal::StackTracer; 55 using v8::internal::TickSample; 56 57 58 static v8::Persistent<v8::Context> env; 59 60 61 static struct { 62 TickSample* sample; 63 } trace_env = { NULL }; 64 65 66 static void InitTraceEnv(TickSample* sample) { 67 trace_env.sample = sample; 68 } 69 70 71 static void DoTrace(Address fp) { 72 trace_env.sample->fp = fp; 73 // sp is only used to define stack high bound 74 trace_env.sample->sp = 75 reinterpret_cast<Address>(trace_env.sample) - 10240; 76 StackTracer::Trace(Isolate::Current(), trace_env.sample); 77 } 78 79 80 // Hide c_entry_fp to emulate situation when sampling is done while 81 // pure JS code is being executed 82 static void DoTraceHideCEntryFPAddress(Address fp) { 83 v8::internal::Address saved_c_frame_fp = 84 *(Isolate::Current()->c_entry_fp_address()); 85 CHECK(saved_c_frame_fp); 86 *(Isolate::Current()->c_entry_fp_address()) = 0; 87 DoTrace(fp); 88 *(Isolate::Current()->c_entry_fp_address()) = saved_c_frame_fp; 89 } 90 91 92 // --- T r a c e E x t e n s i o n --- 93 94 class TraceExtension : public v8::Extension { 95 public: 96 TraceExtension() : v8::Extension("v8/trace", kSource) { } 97 virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction( 98 v8::Handle<String> name); 99 static v8::Handle<v8::Value> Trace(const v8::Arguments& args); 100 static v8::Handle<v8::Value> JSTrace(const v8::Arguments& args); 101 static v8::Handle<v8::Value> JSEntrySP(const v8::Arguments& args); 102 static v8::Handle<v8::Value> JSEntrySPLevel2(const v8::Arguments& args); 103 private: 104 static Address GetFP(const v8::Arguments& args); 105 static const char* kSource; 106 }; 107 108 109 const char* TraceExtension::kSource = 110 "native function trace();" 111 "native function js_trace();" 112 "native function js_entry_sp();" 113 "native function js_entry_sp_level2();"; 114 115 v8::Handle<v8::FunctionTemplate> TraceExtension::GetNativeFunction( 116 v8::Handle<String> name) { 117 if (name->Equals(String::New("trace"))) { 118 return v8::FunctionTemplate::New(TraceExtension::Trace); 119 } else if (name->Equals(String::New("js_trace"))) { 120 return v8::FunctionTemplate::New(TraceExtension::JSTrace); 121 } else if (name->Equals(String::New("js_entry_sp"))) { 122 return v8::FunctionTemplate::New(TraceExtension::JSEntrySP); 123 } else if (name->Equals(String::New("js_entry_sp_level2"))) { 124 return v8::FunctionTemplate::New(TraceExtension::JSEntrySPLevel2); 125 } else { 126 CHECK(false); 127 return v8::Handle<v8::FunctionTemplate>(); 128 } 129 } 130 131 132 Address TraceExtension::GetFP(const v8::Arguments& args) { 133 // Convert frame pointer from encoding as smis in the arguments to a pointer. 134 CHECK_EQ(2, args.Length()); // Ignore second argument on 32-bit platform. 135 #if defined(V8_HOST_ARCH_32_BIT) 136 Address fp = *reinterpret_cast<Address*>(*args[0]); 137 #elif defined(V8_HOST_ARCH_64_BIT) 138 int64_t low_bits = *reinterpret_cast<uint64_t*>(*args[0]) >> 32; 139 int64_t high_bits = *reinterpret_cast<uint64_t*>(*args[1]); 140 Address fp = reinterpret_cast<Address>(high_bits | low_bits); 141 #else 142 #error Host architecture is neither 32-bit nor 64-bit. 143 #endif 144 printf("Trace: %p\n", fp); 145 return fp; 146 } 147 148 149 v8::Handle<v8::Value> TraceExtension::Trace(const v8::Arguments& args) { 150 DoTrace(GetFP(args)); 151 return v8::Undefined(); 152 } 153 154 155 v8::Handle<v8::Value> TraceExtension::JSTrace(const v8::Arguments& args) { 156 DoTraceHideCEntryFPAddress(GetFP(args)); 157 return v8::Undefined(); 158 } 159 160 161 static Address GetJsEntrySp() { 162 CHECK_NE(NULL, i::Isolate::Current()->thread_local_top()); 163 return Isolate::js_entry_sp(i::Isolate::Current()->thread_local_top()); 164 } 165 166 167 v8::Handle<v8::Value> TraceExtension::JSEntrySP(const v8::Arguments& args) { 168 CHECK_NE(0, GetJsEntrySp()); 169 return v8::Undefined(); 170 } 171 172 173 v8::Handle<v8::Value> TraceExtension::JSEntrySPLevel2( 174 const v8::Arguments& args) { 175 v8::HandleScope scope; 176 const Address js_entry_sp = GetJsEntrySp(); 177 CHECK_NE(0, js_entry_sp); 178 CompileRun("js_entry_sp();"); 179 CHECK_EQ(js_entry_sp, GetJsEntrySp()); 180 return v8::Undefined(); 181 } 182 183 184 static TraceExtension kTraceExtension; 185 v8::DeclareExtension kTraceExtensionDeclaration(&kTraceExtension); 186 187 188 static void InitializeVM() { 189 if (env.IsEmpty()) { 190 v8::HandleScope scope; 191 const char* extensions[] = { "v8/trace" }; 192 v8::ExtensionConfiguration config(1, extensions); 193 env = v8::Context::New(&config); 194 } 195 v8::HandleScope scope; 196 env->Enter(); 197 } 198 199 200 static bool IsAddressWithinFuncCode(JSFunction* function, Address addr) { 201 i::Code* code = function->code(); 202 return code->contains(addr); 203 } 204 205 static bool IsAddressWithinFuncCode(const char* func_name, Address addr) { 206 v8::Local<v8::Value> func = env->Global()->Get(v8_str(func_name)); 207 CHECK(func->IsFunction()); 208 JSFunction* js_func = JSFunction::cast(*v8::Utils::OpenHandle(*func)); 209 return IsAddressWithinFuncCode(js_func, addr); 210 } 211 212 213 // This C++ function is called as a constructor, to grab the frame pointer 214 // from the calling function. When this function runs, the stack contains 215 // a C_Entry frame and a Construct frame above the calling function's frame. 216 static v8::Handle<Value> construct_call(const v8::Arguments& args) { 217 i::StackFrameIterator frame_iterator; 218 CHECK(frame_iterator.frame()->is_exit()); 219 frame_iterator.Advance(); 220 CHECK(frame_iterator.frame()->is_construct()); 221 frame_iterator.Advance(); 222 i::StackFrame* calling_frame = frame_iterator.frame(); 223 CHECK(calling_frame->is_java_script()); 224 225 #if defined(V8_HOST_ARCH_32_BIT) 226 int32_t low_bits = reinterpret_cast<int32_t>(calling_frame->fp()); 227 args.This()->Set(v8_str("low_bits"), v8_num(low_bits >> 1)); 228 #elif defined(V8_HOST_ARCH_64_BIT) 229 uint64_t fp = reinterpret_cast<uint64_t>(calling_frame->fp()); 230 int32_t low_bits = static_cast<int32_t>(fp & 0xffffffff); 231 int32_t high_bits = static_cast<int32_t>(fp >> 32); 232 args.This()->Set(v8_str("low_bits"), v8_num(low_bits)); 233 args.This()->Set(v8_str("high_bits"), v8_num(high_bits)); 234 #else 235 #error Host architecture is neither 32-bit nor 64-bit. 236 #endif 237 return args.This(); 238 } 239 240 241 // Use the API to create a JSFunction object that calls the above C++ function. 242 void CreateFramePointerGrabberConstructor(const char* constructor_name) { 243 Local<v8::FunctionTemplate> constructor_template = 244 v8::FunctionTemplate::New(construct_call); 245 constructor_template->SetClassName(v8_str("FPGrabber")); 246 Local<Function> fun = constructor_template->GetFunction(); 247 env->Global()->Set(v8_str(constructor_name), fun); 248 } 249 250 251 // Creates a global function named 'func_name' that calls the tracing 252 // function 'trace_func_name' with an actual EBP register value, 253 // encoded as one or two Smis. 254 static void CreateTraceCallerFunction(const char* func_name, 255 const char* trace_func_name) { 256 i::EmbeddedVector<char, 256> trace_call_buf; 257 i::OS::SNPrintF(trace_call_buf, 258 "function %s() {" 259 " fp = new FPGrabber();" 260 " %s(fp.low_bits, fp.high_bits);" 261 "}", 262 func_name, trace_func_name); 263 264 // Create the FPGrabber function, which grabs the caller's frame pointer 265 // when called as a constructor. 266 CreateFramePointerGrabberConstructor("FPGrabber"); 267 268 // Compile the script. 269 CompileRun(trace_call_buf.start()); 270 } 271 272 273 // This test verifies that stack tracing works when called during 274 // execution of a native function called from JS code. In this case, 275 // StackTracer uses Isolate::c_entry_fp as a starting point for stack 276 // walking. 277 TEST(CFromJSStackTrace) { 278 // BUG(1303) Inlining of JSFuncDoTrace() in JSTrace below breaks this test. 279 i::FLAG_use_inlining = false; 280 281 TickSample sample; 282 InitTraceEnv(&sample); 283 284 InitializeVM(); 285 v8::HandleScope scope; 286 // Create global function JSFuncDoTrace which calls 287 // extension function trace() with the current frame pointer value. 288 CreateTraceCallerFunction("JSFuncDoTrace", "trace"); 289 Local<Value> result = CompileRun( 290 "function JSTrace() {" 291 " JSFuncDoTrace();" 292 "};\n" 293 "JSTrace();\n" 294 "true;"); 295 CHECK(!result.IsEmpty()); 296 // When stack tracer is invoked, the stack should look as follows: 297 // script [JS] 298 // JSTrace() [JS] 299 // JSFuncDoTrace() [JS] [captures EBP value and encodes it as Smi] 300 // trace(EBP) [native (extension)] 301 // DoTrace(EBP) [native] 302 // StackTracer::Trace 303 304 CHECK(sample.has_external_callback); 305 CHECK_EQ(FUNCTION_ADDR(TraceExtension::Trace), sample.external_callback); 306 307 // Stack tracing will start from the first JS function, i.e. "JSFuncDoTrace" 308 int base = 0; 309 CHECK_GT(sample.frames_count, base + 1); 310 311 CHECK(IsAddressWithinFuncCode("JSFuncDoTrace", sample.stack[base + 0])); 312 CHECK(IsAddressWithinFuncCode("JSTrace", sample.stack[base + 1])); 313 } 314 315 316 // This test verifies that stack tracing works when called during 317 // execution of JS code. However, as calling StackTracer requires 318 // entering native code, we can only emulate pure JS by erasing 319 // Isolate::c_entry_fp value. In this case, StackTracer uses passed frame 320 // pointer value as a starting point for stack walking. 321 TEST(PureJSStackTrace) { 322 // This test does not pass with inlining enabled since inlined functions 323 // don't appear in the stack trace. 324 i::FLAG_use_inlining = false; 325 326 TickSample sample; 327 InitTraceEnv(&sample); 328 329 InitializeVM(); 330 v8::HandleScope scope; 331 // Create global function JSFuncDoTrace which calls 332 // extension function js_trace() with the current frame pointer value. 333 CreateTraceCallerFunction("JSFuncDoTrace", "js_trace"); 334 Local<Value> result = CompileRun( 335 "function JSTrace() {" 336 " JSFuncDoTrace();" 337 "};\n" 338 "function OuterJSTrace() {" 339 " JSTrace();" 340 "};\n" 341 "OuterJSTrace();\n" 342 "true;"); 343 CHECK(!result.IsEmpty()); 344 // When stack tracer is invoked, the stack should look as follows: 345 // script [JS] 346 // OuterJSTrace() [JS] 347 // JSTrace() [JS] 348 // JSFuncDoTrace() [JS] 349 // js_trace(EBP) [native (extension)] 350 // DoTraceHideCEntryFPAddress(EBP) [native] 351 // StackTracer::Trace 352 // 353 354 CHECK(sample.has_external_callback); 355 CHECK_EQ(FUNCTION_ADDR(TraceExtension::JSTrace), sample.external_callback); 356 357 // Stack sampling will start from the caller of JSFuncDoTrace, i.e. "JSTrace" 358 int base = 0; 359 CHECK_GT(sample.frames_count, base + 1); 360 CHECK(IsAddressWithinFuncCode("JSTrace", sample.stack[base + 0])); 361 CHECK(IsAddressWithinFuncCode("OuterJSTrace", sample.stack[base + 1])); 362 } 363 364 365 static void CFuncDoTrace(byte dummy_parameter) { 366 Address fp; 367 #ifdef __GNUC__ 368 fp = reinterpret_cast<Address>(__builtin_frame_address(0)); 369 #elif defined _MSC_VER 370 // Approximate a frame pointer address. We compile without base pointers, 371 // so we can't trust ebp/rbp. 372 fp = &dummy_parameter - 2 * sizeof(void*); // NOLINT 373 #else 374 #error Unexpected platform. 375 #endif 376 DoTrace(fp); 377 } 378 379 380 static int CFunc(int depth) { 381 if (depth <= 0) { 382 CFuncDoTrace(0); 383 return 0; 384 } else { 385 return CFunc(depth - 1) + 1; 386 } 387 } 388 389 390 // This test verifies that stack tracing doesn't crash when called on 391 // pure native code. StackTracer only unrolls JS code, so we can't 392 // get any meaningful info here. 393 TEST(PureCStackTrace) { 394 TickSample sample; 395 InitTraceEnv(&sample); 396 InitializeVM(); 397 // Check that sampler doesn't crash 398 CHECK_EQ(10, CFunc(10)); 399 } 400 401 402 TEST(JsEntrySp) { 403 InitializeVM(); 404 v8::HandleScope scope; 405 CHECK_EQ(0, GetJsEntrySp()); 406 CompileRun("a = 1; b = a + 1;"); 407 CHECK_EQ(0, GetJsEntrySp()); 408 CompileRun("js_entry_sp();"); 409 CHECK_EQ(0, GetJsEntrySp()); 410 CompileRun("js_entry_sp_level2();"); 411 CHECK_EQ(0, GetJsEntrySp()); 412 } 413